Three light sources A , B , and C emit an identical amount of radiant energy per unit time. The wavelengths produced by the three sources are 450 nm , 555 nm , and 700 nm , respectively. If X_A , X_B , and X_C represent the brightness sensed by an eye for each source, respectively, then

Step-by-step solution

The human eye is most sensitive to yellow-green light, which has a wavelength of 555 nm . The relative luminosity curve of the human eye peaks at 555 nm and decreases for both shorter and longer wavelengths. Since sources A , B , and C emit the same amount of radiant energy per unit time, the brightness sensed by the eye is directly proportional to the relative luminosity at their respective wavelengths. Because the sensitivity is maximum at 555 nm (source B ), the brightness sensed for source B will be greater tha